A membrane composite polymer liquid crystal of Polymethyl Methacrylate with Mesogen Reactive 257, doped with lithium ions (PMMA-RM257-Li), has been successfully synthesized. Synthesized PMMA-RM257-Li using methods of UV exposure to polymer solutions and were made with RM257 variations of 10, 30, 50, 70 and 90 wt.%. Membrane composite polymer PMMA-RM257-Li was characterized by FTIR where absorption peaks appear at wavenumbers 2935 cm−1 indicating the-CH3 functional group, 1730 cm−1 indicating the C=O functional group, and 1630–1660 cm−1 indicating the presence of aromatic groups. Analysis of crystallinity by XRD results showed that the membrane polymer PMMA-RM257-Li is semicrystalline. The composite membrane obtained optimum test results at the addition of 50 wt.% RM257 with an ionic conductivity of 1.01 × 10−3 S/cm and an ion exchange capacity value of 0.02385 meq/g. This study shows that the addition of 50 wt.% RM257 provides the most optimal membrane characteristic results. The characterization results showed that the addition of lithium ions to the manufacture of PMMA-RM257 membranes improved the membrane's capabilities for membrane fuel cell technology.

A simple high-performance liquid chromatography (HPLC) method has been developed in this study for enantioseparation and determination of ibuprofen in tablet samples. The HPLC method utilized an α-acid glycoprotein (AGP) as the stationary phase (10 cm × 4.0 mm × 5 µm) with 100 mM phosphate buffer (pH 7) as the mobile phase at a flow rate of 0.7 mL/min, and UV detection at 225 nm. Enantioseparation of ibuprofen has been successfully achieved by the optimized HPLC with a resolution greater than 1.50 and a retention time of less than 9 minutes. The calibration curve was linear for ibuprofen over the concentration range of 25 to 100 mg/L of standards with r higher than 0.996. The results show excellent average recoveries (83.20%, n = 3) for ibuprofen in the pharmaceutical (tablet) sample.

Membrane composite polymer liquid crystal of Polymethyl Methacrylate with Mesogen Reactive Diacrylate (PMMA-RMDiacrylate) has been successfully synthesized. This research report of the synthesized and characterizations of PMMA-RMDiacrylate and analysis of capacitance and resistance. The purpose of this research is study of capacitance and resistance of membrane composite polymer PMMA-RMDiacrylate for membrane electrolyte in fuel cell system. Synthesized membrane composite polymer of PMMA-RMDiacrylate using methods of UV exposure to polymer solutions and addition of a Benzoyl Peroxide (BPO) initiator. Membrane composites polymer PMMA-RMDiacrylate were made with RMDIACRYLATE weight percent variations of 20%, 30%, and 40%. Membrane composite polymer PMMA-RMDiacrylate was characterized by FTIR that absorption peaks appear at wave numbers 2927 cm −1 indicating the −CH 3 functional group, 1722 cm −1 indicating the C=O functional group, 1602 cm −1 indicating the presence of aromatic groups, 1248 cm −1 indicating the C−O−C group, 1060-1144 cm −1 indicating the C−O functional group. Texture and morphology analysis of membrane composite polymer of PMMA-RMDiacrylate showed effect of variations concentrations of RMDiacrylate. Analysis crystallinity by XRD results showed that the composite membrane polymer PMMA-RMDiacrylate is semicrystalline and sharp peaks appear as an indicator of phase crystallinity in the PMMA-RMDiacrylate membrane. Electrical properties of composite membrane of PMMA-RMDiacrylate using an LCR meter shows an increase in capacitance, resistance in sensors with 30% and 40% RMDiacrylate variations showed a decrease. The increasing concentration of RMDiacrylate in membrane composite polymer of PMMA-RMDiacrylate has good electrical properties.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Asep Riswoko, Silva Abraham, Teguh Baruji, Rizka Gitami Sativa, Fajriyan, Eko Santoso, I. Gede Eka Perdana Putra, Noorendra Laksamana Putra, Muhson Isroni, Abdul Wakhid Shodiq, Isni Nasrifah, Amalia Fitria, Johadi, Intan Machiya, Priyo Wahyudi, Irwandhi; Utilization of polymeric coated urea enriched with beneficial soil bacteria. AIP Conf. Proc. 28 February 2024; 3003 (1): 020019. https://doi.org/10.1063/5.0186208 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Abstract Mesogen reactive RM257 and cholesteryl acrylate are two types of liquid crystal with the characteristic property of possesing polymerizable groups. Cholesteryl acrylate has interesting properties that can form a helical spiral structure. Previous research in maintaining the helical structure has not been maximized. In this study, we will explain how the UV curing process is a way to fix the helical structure. Monomer phase of cholesteryl acrylate only appears at mesophase temperature, in order to maintain the helical structure of the cholesterl acrylic compound is polymerized. Mesogen reactive RM257 is monomer liquid crystal that acrylate functions as back bone polymer chain. Cholesteryl acrylate and RM257 each monomers is polymerized using UV light with 55 watt of wavelength which has 365 nm. The polymerization process produces a new functional group formed by C-O esters at wave numbers 1047 cm−1 and 1055 cm−1. XRD diffraction pattern showed peaks at 2θ in 7.5°,15°, and 20°. Photo SEM image showed crosslinked morphology structure. Based on the results of this study, it is hoped that the polymer RM257 and acrylate coliform can be smart materials for sensor applications and further technological material composites.

This research report of the synthesis of composite polymers from liquid crystal mesogen reactive (RM82) monomers with Methyl methacrylate (MMA). The purpose of this research is analysis the effect concentration of MMA on the surface and thermal of the composite polymer PMMA-RM82. The result of the morphological analysis of composite surfaces performed by polarization optical microscopy (POM) technique showed liquid crystal textures affected composition from two monomers. SEM images show that the surface of the RM82 liquid crystal has a shape resembling fibrous and blade-like crystals with a length of up to 10 μm (micrometers). Analysis thermal showed the heat released by the PMMA-RM82 increased with the increase in MMA weight percent. This affects the rapid crystallization process of PMMA-RM82 which of concentration MMA 30%-RM82 the heat released is almost twice as much as the heat released by MMA 5%-RM82. The absence of PMMA and RM82 peaks both endothermic and exothermic in PMMA-RM82 samples indicates that polymerization has occurred and a new product has formed. Analysis structure molecule by FTIR found that the IR spectral form of each variation in the weight percent of MMA was almost the same, but there was a spectral shift that showed that polymerization had occurred in PMMA-RM82 which was characterized by a reaction to the free radical C=C bond released by the photoinitiator. XRD pattern of composite PMMA-RM82 showed the peaks formed are located at scattering angles similar to RM82 but there is a decrease in intensity as the percent weight of MMA increases.

A method to determine aceclofenac, ketorolac, and sulindac in human urine samples using microemulsion electrokinetic chromatography (MEEKC) has been developed in this study. The optimization of MEEKC conditions was carried out by changing the microemulsion compositions including the buffer pH, borate salt concentration, surfactant concentration, co-surfactant concentration, organic modifier concentration, and oil droplet concentration. The optimum separation of selected drugs was obtained with a composition of microemulsion containing 10 mM borate buffer pH 9, 0.5% sodium dodecyl sulphate (SDS), 6.6% n-butanol, 6.0% acetonitrile, and 0.8% ethyl acetate. Excellent linearity was obtained in the range concentration of 25 to 200 ppm with r2 > 0.999. Limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) were 2.72 to 4.75 and 9.08 to 15.85 ppm, respectively. The solid-phase extraction (SPE) method using C-18 as an adsorbent and the solid phase micro-tip extraction (SPMTE) method using multiwalled carbon nanotubes (MWCNTs) as an adsorbent were used to clean-up and pre-concentrate the urine samples prior to the MEEKC analysis. The best recoveries of the selected drugs in the spiked urine sample were 91 to 103% with RSD of 1.26 to 4.03% (n = 3) using the SPE-MEEKC method.

Patients with end-stage kidney disease on hemodialysis (ESKD-HD) have a high risk of contracting severe COVID-19. Vaccination can help reduce disease severity, but the immune dysregulation observed in these patients may result in an inadequate antibody response. Therefore, we aimed to evaluate the immune response postvaccination in ESKD-HD patients. This prospective cohort study was conducted in two hemodialysis centers in Indonesia. We enrolled ESKD-HD patients (n = 143) pre- and postvaccination and compared them to healthy subjects (n = 67). SARS-CoV-2 antibody response was assessed using anti-S-RBD antibodies and SVNT % inhibition tests. We performed bivariate and multivariate analysis to determine factors associated with SARS-CoV-2 antibody levels. Seropositive conversion was observed in 97% ESKD-HD subjects postvaccination. Compared with healthy subjects, ESKD-HD patients showed a comparable anti-S-RBD antibody titer postvaccination. mRNA vaccines remained a significant factor for the high immune response, while hypoalbuminemia correlated with lower immune response. In conclusion, ESKD-HD patients showed a robust immune response postvaccination. mRNA vaccines induced a stronger antibody response than other vaccines. Lower levels of serum albumin correlate with lower immune responses in ESKD-HD patients after vaccination.

The development of efficient enantioselective detection, analysis, and separation relies significantly on molecular interaction. In the scale of molecular interaction, nanomaterials have a significant influence on the performance of enantioselective recognitions. The use of nanomaterials for enantioselective recognition involved synthesizing new materials and immobilization techniques to produce various surface-modified nanoparticles that are either encapsulated or attached to surfaces, as well as layers and coatings. The combination of surface-modified nanomaterials and chiral selectors can improve enantioselective recognition. This review aims to offer engagement insights into the production and application of surface-modified nanomaterials to achieve sensitive and selective detection, better chiral analysis, and separation of numerous chiral compounds.

Liquid crystal composite is a material made from monomer liquid crystal with other materials. These composites are very useful because they combine good properties of each material for many applications. Liquid crystal diacrylate resin of 2-methyl-1,4-phenylene bis(4-(3-(acryloyloxy) propoxy)benzoate) that combined with monomer methyl methacrylate (MMA) using casting solution method. Process casting solution of that material using variation weight percentage of each material. Result of casting solution was photopolymerized using preparate glass to make a thin layer polymer. Characterization thin layer polymer liquid crystal diacrylate resin with MMA using instrumentations FTIR for identify of chemical group functions molecules. FTIR spectrum showed peak at 1155 cm −1 -1160 cm −1 for identifications stretching vibration of C-O-C in ester molecule and 2925-2960 cm −1 for identifying the stretching vibration of –CH 3 . Its band for identify bond formation between MMA with diacrylate resin. Diffractogram XRD showed thin layer polymer of PMMA-diacrylate resin has amorphous properties, because there aren’t sharp peak diffraction at 2θ 16.33°, 24.02°, 44.68°, and 72.54°. This result indicates that thin monomer methyl methacrylate blending perfect with diacrylate resin. Therefore analysis morphology of thin layer liquid crystal composite of PMMA-diacrylate resin homogen in some regions but in a little surface seen agglomeration of polymer.

The SARS-CoV-2 virus that caused pandemic COVID-19 has spread rapidly to humans and causes a very serious health and social problem around the world. In order to develop vaccine and therapeutic approaches, a comprehensive study of viral structure and viral biological infection needs to be understood. In addition to four structural proteins; spike glycoprotein (S), envelope (E), membrane protein (M), and nucleocapsid protein (N), SARS-CoV-2 viral genome, consist of two open reading frame (ORF) which is located in N-terminus, ORF1a, and ORF1b. The ORF1a consist of Main protease (3CLpro) and together with papain-like protease (PLpro) play a role in the cleavage of polyproteins and translated from viral RNA to mature protein. Here we describe a method of production of 6xHis-tagged Papain-like protease fragment in E. coli RIPL, including gene expression, solubilization of inclusion bodies by different methods, and detection of gene product target by Western Blot Analyses.

Coronavirus disease-19 (COVID-19) pandemic caused millions of deaths and socio-economics damage worldwide. Corresponding to this, many studies on antiviral drugs exploration are rising to investigate the potential of drug compounds that can repress the replication of the SARS-CoV-2 virus by targeting its main protease named 3-chymotrypsin like protease (3CLpro). Without 3CLpro splicing, polyproteins of SARS-CoV-2 will not function to form new virions. We conducted an in silico thermodynamic study, and found several already known compounds from natural sources such as lovastatin, quinidine, and quinine were potential in inhibiting 3CLpro. However, most of the findings still need further wet-lab experiments to confirm their activity against it. To facilitate rapid screening of protease inhibitors, we aim to develop a screening kit for researchers with focus studies on herbal sources for COVID-19 treatments. Hence, the development of 3CLpro as the target of inhibition screening is essential. Our current work focused on the expression of the SARS-CoV-2 3CL Pro gene harbored by pET-32b(+) in E. coli BL21(DE3) and its purification. The recombinant E.coli were cultivated in LB media at 37 °C with 5 hours IPTG-induced phase followed by crude protein lysate extraction by sonication, and then Ni-NTA purification. A band of recombinant 3CLpro protein (33.8 kDa) detected by SDS PAGE and Western blotting after Ni-NTA purification was specific and clear, showing the right size of our protein interest. A final concentrated protein mixture obtained by 10-kDa membrane filtration displayed >90% purity with a total protein of 2.497 mg mL−1. Further functional assays and inhibitory tests with several natural compounds showed that 3CLpro functioned well as a drug target.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus that has caused the corona pandemic since 2019 or known as Covid-19. The cleavage of its polyprotein started this viral replication into functional viral proteins by two proteases: 3-chymotrypsin-like protease (3CL protease), also known as main protease (Mpro), and Papain-like protease (PLpro). Medicinal plant bioactive constituents could potentially become protease inhibitor agents of this virus and prevent viral replication. Thus, further might be developed into drug candidates for diseases with no specific drug currently available. The first step of discovering the medicine is virtual screening with a molecular docking simulation approach. The stable conformation structure of the bioactive compounds was docked into the enzymes SARS-CoV-2 Main Protease (PDB ID: 6XMK) and SARS-CoV-2 Papain-Like Protease (PDB ID: 7CMD). Molecular docking simulations were operated using Molegro Virtual Docker (MVD) program after the validation process. In this study, analysis of the docking simulation was carried out of compounds in Andrographis paniculata, Phyllanthus niruri L., Aloe vera , and Sonchus arvensis. They are medicinal plants that have been used as a medicine for generations and may have potential as antivirals. A docking score with a more negative presentation binding energy value has a more significant potential to be a lead compound. Several potential compounds were evaluated for their absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. This method can reduce the trial and error factor in the drug discovery stage, although it needs further proof by experimentation in a wet laboratory.

Ramie fiber is a potential raw material to substitute imported raw materials such as cotton. Due to its higher hemicellulose content, ramie fiber required hydrolysis in a process called degumming. Enzymatic degumming is environmentally friendly compared to traditional process which using chemicals. Alkalithermophilic xylanase have high ability in hemicellulose hydrolysis. The production of xylanase was conducted by submerged fermentation of Bacillus halodurans CM1 in 20L bioreactor using Mamo and corncob medium with optimum conditions at 50°C, pH 9, 150 RPM and 1 vvm. The optimum specific activity of xylanase measured by Bailey method at 70°C and pH 9 is 475.41 U/mg. Xylanase was stable at 50°C, pH 9 and relatively stable to K+, Na2+, Co2+ and Ca2+ metal ions and Triton-X, Saba dan Tween-80 surfactants. Degumming process was carried out by immersing ramie fibers in formulated degumming solution with vlot 1:20 at 50°C, 150 RPM and 180 minutes. The enzymatic degumming process may substitute or reduce the use of chemicals due to its significant effect on ramie fiber quality. Enzymatic and chemical degumming process reduce the weight of Ramie Fiber to 7.23 %, and 7.72 %, slightly higher than enzymatic degumming 7.15%. Enzymatic degumming maintains tensile strength at 27.51 %. Whiteness index enhanced to 2.99% enzymatically and 3.49% chemically. Keywords: Bacillus halodurans CM1, enzymatic degumming, ramie fiber, textile industry, thermoalkaliphilic xylanase

Scaffold is a 3-dimensional matrix created as a new bone cell growth medium made from natural polymers and bioceramics. The extracted pectin from green Cincau leaves (Premna oblongifolia Merr) and hydroxyapatite (HA) are used in the manufacture of scaffolds. Pectin was extracted using citric acid with variation concentration of 0, 0.1, 0.2 and 0.3% (w / v). The 3% (w / w) HA-pectin mixture, dried freeze using a freeze dryer. The characterization of extracted pectin and HA-pectin scaffold was then performed. The results showed that pectin of green Cincau leaves had low methoxyl content, which was 1.364 to 5.022%. The resulting scaffold has a pore size ranging from 8.25 to 115 µm while the scaffold resistance to the load, ie 0.03 to 0.15 MPa. The scaffold porosity that has been made is 15.33 to 40.97% while the density is 0.69 to 1.02 g/cm3.

SINTESIS DAN KARAKTERISASI STRUKTUR KRISTALCAIR FEROELEKTRIKTIPE ESTER BENZOAT TURUNAN DARIASAM (S)-(+)-2-METILBUTANOAT . Metode sintesis kristal cair feroelektrik tipe ester benzoat turunan dari asam (S)-(+)-2-metil butanoat telah berhasil dikembangkan melalui metode esterifikasi (S)-(+)-p-hidroksifenil-2-metilbutanoat ((S)-(+)-2-HFM) dengan akriloksi butiloksi benzoat (ABB). Senyawa kiral alkohol (S)-(+)-2-HFM diperoleh dengan esterifikasi Steglich menggunakan hidrokuinon dengan katalis disikloheksil karbodiimida (DCC) dan dimetil amino piridin (DMAP). Sedangkan akrilat ABB diperoleh dari hasil sintesis senyawa induk asam 4-klorobutil asetat melalui pembentukan eter Williamson yang diikuti hidrolisis basa dan dilanjutkan dengan akrilasi. Karakterisasi struktur kristal cair feroelektrik yang berasal dari kedua prekursor ini dengan Fourier Transform - Infra Red ( FT-IR ) menunjukkan ester dengan gugus karbonil dan fenil tanpa gugus hidroksi. Puncak serapan spektrum FT-IR produk ester (cm -1 ): 3323,53; 2851,03; 2666,01; 1729,09; 1622,86; 1536,74; 1510,75; 1244,16; dan 1170,16.

Observation on the effects of rare earth impurities on the properties of Ce0.9Gd0.1O0.195 (GDC) composite electrolyte has been performed. Indonesia has abundant rare earth elements especially CeO2, which one of the resources is from monazite mineral. In this study, the GDC powders were synthesized via solid state technique. The two types of precursors were prepared and mixed into planetary ballmill, i.e., CeO2 (Sigma Aldrich) with Gd2O3 (Sigma Aldrich) and CeO2 (non-commercial, local product) with Gd2O3 (Sigma Aldrich), namely GDC commercial and GDC non-commercial, respectively. The composite electrolyte powders calcined at temperature of 800°C in the air atmosphere condition. The composite electrolytes were then characterized in terms of its morphology, elemental, phase structure and thermal properties of the powders. The GDC commercial and non-commercial powders both consist of face centered cubic fluorite ceria structure which was confirmed by X-Ray Diffraction (XRD). The peaks are matching well with the cerium oxide JCPDS card No: 34-394. There are no peaks detected for the gadolinium oxide. It indicates that the dopant ion is fully substituted into the CeO2 lattice. The elemental analysis was performed using X-ray Fluorescence (XRF). The microstructures were observed under Scanning Electron Microscopy (SEM). The thermal properties characterizations were performed by using Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) from room temperature to 1500°C. Both powders investigated are suitable for electrolyte IT-SOFC based on their physical and thermal characterization. Among the composite electrolytes investigated, the GDC commercial showed the better performance in terms of their physical and thermal properties.

Limestone which is one of the raw materials for the manufacture of materials and medical devices obtained scattered in almost all provinces in Indonesia.In this paper, the making hydroxyapatite using limestone as the raw material was studied.Synthesis of hydroxyapatite was done using precipitation method.The main material of forming a hydroxyapatite in this study is diammonium hydrogen phosphate and calcination of limestone at 900 0 C for 4 hours that produce calcium oxide (CaO).The pure calcium oxide was observed in order to know the effect of calcium solution addition rate and calcium precursor size.The calcium oxide precursor was prepared with high energy milling (HEM).HEM usage is intended to produce a precursor size of calcium in nano size.Furthermore, the characterization of second phase precursors using x-ray diffraction (XRD), analysis of morphology and element content using scanning electron microscopy-energy dispersive X-ray (SEM-EDX) and analyzes the size and distribution of particles of calcium resulted from milling using a particle size analyzer ( PSA).

Blending cholesteryl acrylate with methyl phenyl benzoyl acrylate was made by casting solution.Photopolymerization of blending product has been done by varying the UV radiation time were 60, 90, 120 and 150 min using UV curing technique.Curing process doing at temperature range of 55-60 °C.Molecular weight (Mw) of polymers was determined using gel permeation chromatography (GPC) showed the first peak at Mw 2243 and the second peak at Mw 1160 and the result of index polydisperity was 1.02-1.03.Polymer of liquid crystal acrylate from this study was characterisized by XRD, SEM-EDX and FTIR.The XRD pattern peaks appear at 60, 90 and 120 min.SEM image shows the crosslink bonds are formed.EDX graph shows the polymer mixture containing carbon and oxygen.The FTIR spectrum raises wavenumber 1612.56 cm -1 indicates that the C=C bonds contained in the polymer structure.Based on the result of characterization of polymer liquid crystal acrylate with XRD, SEM-EDX and FTIR shown that best product was from radiation time polymerization at 90 min.

Liquid crystal is a material which is between solid and liquid phase and commonly called mesophase. Blends of liquid crystal are of great interest because of their unique optical properties. Blending in this study using two monomers of liquid crystal were cholesteryl acrylate and methyl phenyl benzoyl acrylate. The polymerization process using uv curing techniques by irradiation UV ray and without irradiation UV ray. Polymerization of blending liquid crystal acrylate using initiator 2-hydroxy-2-methyl-1-phenylpropane. Based on peak at GPC curve of polymerization by irradiation UV ray, type of that polymer is copolymer. Therefore the polymerization without UV ray, type of that polymer is homopolymer. SEM images of liquid crystal acrylate polymer showed lamella chain models that are characteristic of a polymer chains. Type of polymer liquid crystal acrylate was the type of Side Chain Liquid Crystalline Polymers (SCLCPs). Therefore acrylate polymer liquid crystal in this research has semi-crystalline phase, which contained crystalline phase and amorphous phase on the XRD pattern. The results of FT-IR spectroscopic characterization of the two monomers showed a peak at the wave number of 1600.43 cm -1 and 1622.86 cm-1 which indicates a double bond (C=C) were obtained from acrylation. While the spectroscopy on the product blending the wave number of the peak regions is reduced that shows that carbon double bonds (C=C) in the acrylate group has polymerized. It also strengthened with a very sharp peak for CC functional groups on the wave number of 2855.15 cm-1. The results of this study indicate that the liquid crystal polymer acrylic polymerization results with radiation UV ray and without UV ray, respectively absorb light in the UV wavelength region 363 nm and 351 nm.